MCBEE CARD KEY

Date

Description

McBee punch cards, also known as edge-notched cards, were a data-sorting system developed before computers. Invented in 1896, they were in common use until the 1980s. The cards, most commonly 5”x8” index cards, had holes punched in regular intervals around the edges, and you could write more information in the middle of the card. Each hole corresponded to a particular data category predetermined by the user. To indicate that the card belonged to a particular category, you extended a hole to the edge of the card, making a notch. After aligning all the cards with the help of a slanted corner on each card, you inserted a long needle into the hole representing the category that you desired. All the cards not belonging to that category would stay on the needle for you to lift away; the cards belonging to that category had notches at that spot and thus were left behind for easy retrieval. Further narrowing of the results could be performed by using another set of holes and another needle.

This card was the key card to this data collection project on polio.

Source

The U. S. National Archives and Records Administration at Atlanta, 5780 Jonesboro Road, Morrow, GA 30260 www.archives.gov/atlanta